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1/* FS-Cache latency histogram
2 *
3 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public Licence
8 * as published by the Free Software Foundation; either version
9 * 2 of the Licence, or (at your option) any later version.
10 */
11
12#define FSCACHE_DEBUG_LEVEL THREAD
13#include <linux/module.h>
14#include <linux/proc_fs.h>
15#include <linux/seq_file.h>
16#include "internal.h"
17
18atomic_t fscache_obj_instantiate_histogram[HZ];
19atomic_t fscache_objs_histogram[HZ];
20atomic_t fscache_ops_histogram[HZ];
21atomic_t fscache_retrieval_delay_histogram[HZ];
22atomic_t fscache_retrieval_histogram[HZ];
23
24/*
25 * display the time-taken histogram
26 */
27static int fscache_histogram_show(struct seq_file *m, void *v)
28{
29 unsigned long index;
30 unsigned n[5], t;
31
32 switch ((unsigned long) v) {
33 case 1:
34 seq_puts(m, "JIFS SECS OBJ INST OP RUNS OBJ RUNS RETRV DLY RETRIEVLS\n");
35 return 0;
36 case 2:
37 seq_puts(m, "===== ===== ========= ========= ========= ========= =========\n");
38 return 0;
39 default:
40 index = (unsigned long) v - 3;
41 n[0] = atomic_read(&fscache_obj_instantiate_histogram[index]);
42 n[1] = atomic_read(&fscache_ops_histogram[index]);
43 n[2] = atomic_read(&fscache_objs_histogram[index]);
44 n[3] = atomic_read(&fscache_retrieval_delay_histogram[index]);
45 n[4] = atomic_read(&fscache_retrieval_histogram[index]);
46 if (!(n[0] | n[1] | n[2] | n[3] | n[4]))
47 return 0;
48
49 t = (index * 1000) / HZ;
50
51 seq_printf(m, "%4lu 0.%03u %9u %9u %9u %9u %9u\n",
52 index, t, n[0], n[1], n[2], n[3], n[4]);
53 return 0;
54 }
55}
56
57/*
58 * set up the iterator to start reading from the first line
59 */
60static void *fscache_histogram_start(struct seq_file *m, loff_t *_pos)
61{
62 if ((unsigned long long)*_pos >= HZ + 2)
63 return NULL;
64 if (*_pos == 0)
65 *_pos = 1;
66 return (void *)(unsigned long) *_pos;
67}
68
69/*
70 * move to the next line
71 */
72static void *fscache_histogram_next(struct seq_file *m, void *v, loff_t *pos)
73{
74 (*pos)++;
75 return (unsigned long long)*pos > HZ + 2 ?
76 NULL : (void *)(unsigned long) *pos;
77}
78
79/*
80 * clean up after reading
81 */
82static void fscache_histogram_stop(struct seq_file *m, void *v)
83{
84}
85
86static const struct seq_operations fscache_histogram_ops = {
87 .start = fscache_histogram_start,
88 .stop = fscache_histogram_stop,
89 .next = fscache_histogram_next,
90 .show = fscache_histogram_show,
91};
92
93/*
94 * open "/proc/fs/fscache/histogram" to provide latency data
95 */
96static int fscache_histogram_open(struct inode *inode, struct file *file)
97{
98 return seq_open(file, &fscache_histogram_ops);
99}
100
101const struct file_operations fscache_histogram_fops = {
102 .owner = THIS_MODULE,
103 .open = fscache_histogram_open,
104 .read = seq_read,
105 .llseek = seq_lseek,
106 .release = seq_release,
107};
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* FS-Cache latency histogram
3 *
4 * Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8#define FSCACHE_DEBUG_LEVEL THREAD
9#include <linux/module.h>
10#include <linux/proc_fs.h>
11#include <linux/seq_file.h>
12#include "internal.h"
13
14atomic_t fscache_obj_instantiate_histogram[HZ];
15atomic_t fscache_objs_histogram[HZ];
16atomic_t fscache_ops_histogram[HZ];
17atomic_t fscache_retrieval_delay_histogram[HZ];
18atomic_t fscache_retrieval_histogram[HZ];
19
20/*
21 * display the time-taken histogram
22 */
23static int fscache_histogram_show(struct seq_file *m, void *v)
24{
25 unsigned long index;
26 unsigned n[5], t;
27
28 switch ((unsigned long) v) {
29 case 1:
30 seq_puts(m, "JIFS SECS OBJ INST OP RUNS OBJ RUNS RETRV DLY RETRIEVLS\n");
31 return 0;
32 case 2:
33 seq_puts(m, "===== ===== ========= ========= ========= ========= =========\n");
34 return 0;
35 default:
36 index = (unsigned long) v - 3;
37 n[0] = atomic_read(&fscache_obj_instantiate_histogram[index]);
38 n[1] = atomic_read(&fscache_ops_histogram[index]);
39 n[2] = atomic_read(&fscache_objs_histogram[index]);
40 n[3] = atomic_read(&fscache_retrieval_delay_histogram[index]);
41 n[4] = atomic_read(&fscache_retrieval_histogram[index]);
42 if (!(n[0] | n[1] | n[2] | n[3] | n[4]))
43 return 0;
44
45 t = (index * 1000) / HZ;
46
47 seq_printf(m, "%4lu 0.%03u %9u %9u %9u %9u %9u\n",
48 index, t, n[0], n[1], n[2], n[3], n[4]);
49 return 0;
50 }
51}
52
53/*
54 * set up the iterator to start reading from the first line
55 */
56static void *fscache_histogram_start(struct seq_file *m, loff_t *_pos)
57{
58 if ((unsigned long long)*_pos >= HZ + 2)
59 return NULL;
60 if (*_pos == 0)
61 *_pos = 1;
62 return (void *)(unsigned long) *_pos;
63}
64
65/*
66 * move to the next line
67 */
68static void *fscache_histogram_next(struct seq_file *m, void *v, loff_t *pos)
69{
70 (*pos)++;
71 return (unsigned long long)*pos > HZ + 2 ?
72 NULL : (void *)(unsigned long) *pos;
73}
74
75/*
76 * clean up after reading
77 */
78static void fscache_histogram_stop(struct seq_file *m, void *v)
79{
80}
81
82const struct seq_operations fscache_histogram_ops = {
83 .start = fscache_histogram_start,
84 .stop = fscache_histogram_stop,
85 .next = fscache_histogram_next,
86 .show = fscache_histogram_show,
87};